Opioids (morphine-like drugs) are generating a lot of press these days. New versions of these
drugs such as Oxycontin® (sustained released oxycodone) have become the drug of choice for many
addicts who get a high by grinding the pills and snorting them. The lengths these addicts go in
order to get the pills reads like a bad movie script. They masquerade as medical staff, they get
prescriptions from multiple doctors, they claim to have lost their pills – they become desperate
for a fix.

Yet, opioids are one of the best treatments available for the easing of pain and suffering. They
are highly effective for acute pain, and moderately effective for chronic pain. They are remarkably
free of any tissue toxicity, which means that they do not harm organs even with long-term use.
The main side effects are sedation, constipation, and nausea.

So how did something which has helped thousands of pain sufferers create such a media scare?

The Nature of Addiction

First, let’s try to understand the nature of addiction. Addiction is a psychological condition
characterized by the inappropriate craving and seeking of opioids for reasons other than the treatment
of a medical condition. When opioids are given to patients with addiction problems, their craving
increases and their day-to-day functioning deteriorates. Pain patients, on the other hand, will
report less pain and their day-to-day functioning will improve.

The media, the general public, patients, and even doctors have always had a difficult time understanding
that a person who takes pain medication for a legitimate ailment has an extremely rare
chance of ever becoming addicted to pain pills. This has been borne out in study after study.
Furthermore, almost all studies of pain treatment reveal that pain is undertreated, yet many doctors
fear providing proper pain treatment, and a great many people suffer needlessly.

Fear of addiction is what is driving the current media frenzy about these medications.
The focus of attention should be on discerning who is an abuser while still making sure that the
person with legitimate pain gets the medication necessary for recovery. Monitoring that medication
is used as prescribed, and checking for improvement of patient functioning, will help the clinician
screen for patients with addiction problems.

Exciting Pain Medication Breakthroughs

Let’s take a quick look at the new science underlying the use of opioids. The nervous system
functions by the transmission of nerve signals from one nerve cell (neuron) to another. One neuron
releases a small amount of chemical (called a neurotransmitter) which fits like a puzzle into
the next nerve and activates a receptor. Thus, the pain signal travels from one location to the
next until it reaches the brain and causes the sensation of pain. Opioids act like brakes. They
activate opioid receptors, which inhibit the neuron, making it is less likely to transmit the
pain signal.

There is increasing data that the most effective form of pain management is prevention (see our last Update, March 2001-Preventing Chronic Pain). The newer long-acting or sustained release opioid medications provide steady opioid blood levels, which may help to prevent pain (rather than the more difficult task of trying to catch up
after the pain has become severe).

There are several new discoveries about how opioids affect pain signal transmission:

It has recently been discovered that some opioids do not only activate opioid receptors, but
are also blockers of the NMDA (n-methyl-d-aspartate) receptor. NMDA blockers may actually decrease
the development of both chronic pain as well as opioid tolerance.

Some opioids have been found to inhibit the nervous system’s disposal of the neurotransmitters
norepinephrine and serotonin. Since these neurotransmitters also act to inhibit pain transmission,
this ability may have important analgesic effects.

Methadone is a particularly interesting opioid because it binds to a recently described sub-type
of the opioid receptors, the mu3 receptor. This receptor is found in significant
quantities on immune system cells, and may help to diminish pain by decreasing the inflammatory
response. (Caution must be used in administering this medication because it’s long half-life
can lead to accumulating blood levels.)

Exciting work is also being carried out on the anti-cancer effects of opioids, specifically methadone
and morphine, which appear to induce apoptosis, (a form of cellular suicide) which helps to prevent
the growth of human cancer cells and tumors.

The ominous press reports notwithstanding, there is much to be excited about with the new pain
medication tools we have!